Producing quartz-glass free from air-bubbles.



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*"pnob'tiemq QuAnTZ'rGLAss FREE gen om IAm-B'UB B ESH useful Glass To all 1072,0171) it Witty "concern:

- "Beit known thatI, RICHARD K6011, asubject of theGermanperor, and a resident of Hanan, Ger any, have invented certain new and Free from AinB ubbles, of which the followingiisfa specification.

r c -c ystal is} well kn own-, 1uartz glass is melted It is comparativelyeasy to melt rockfiry'stahas "it-is only'nece'ssary to heat thefraw material-in vessels of carbon or iridi um ,up toa tem perature ofover 1,700 centigrade either inan electric furnace or in a fur- 'nace. w th an oxyhydrogen-blowpipe; The

quartz glass so produced contains, however, numerous large air-bubbles, even if all other impurities are. avoided. These air-bubbles u arise' fromtwo caujsesi-first, the rock-crystal is employedrin a coarsely pulverized state, so

that jduring the melting process the air .betweennthe severalpieces or come is inclosed bry themeltingmass, and it is very hard to make thisair rise inthe liquid mass even by longrcontinuedheating up to a very high temperature, .andit ismost probable that this air cannot be extractedat 'allin a practical man'-' ner'; second,'duri'ng the heating without spei, facial precautions-the rock crystal is apt to burst intonumerous pieces, so that later on during the melting process not only the quantity, but

,. alsothesize ottheair-bubbles formed in the mass-in th'emanner'i-ndicated above will be "furtherincreased; -"Shenstonehas endeavored about -1',( )00 centigrade.

to -avoid the formationof the numerous and lar'gegair-bubhles :in the quartz-glass by suddenly chilling with 'cold water the pieces that haveremainedintact during the heating up to Such chilled pieces look ,white, like milk, since-theyhave been =th ree important facts, vizz F11 divided into exceedingly small particles, without,'-how'ever,"losing: their external cohesion.

These chilled piecescan beat once exposed to crystal heated up to a temperature of over 600 c'entigrade will burst more violently into Specification of Letters Patent- Application filed November 17, 190;. swarm. 233.214,,

"Improvements in Producing Quartzst,- during a smaller'pieces if they are then cooled; third,

those pieces ofrock-crystal which have not burst during their heating up'to-adzempera-1 centigradeorshow, at any ture of over 600 rate,'but insignificant cracks or crazes canbe at once'put to the highest temperature without further bursting, care being'taken that These three V vfacts have led me toinvent a new method of theyare not cooled, meanwhile.

producing quartz-glass free t'rom air-bubbles.

This method is as follows: A convenient quantity of pieces of rock-crystal in the size I of from a hazelnut up to a walnut is placed in acrucible or other similar vessel and heated very slowly up to a temperature exceeding GOO centigrade. Afterward with the aid of a suitable heated implement or tool (such as a pair of tongsor thelike) a piece is extracted from the glowing contents of the crucible or vessel and at once exposed to the temperature required for the vitrification, care being taken to avoid every cooling. This vitrification may.

be effected in two mannerseither the piece is exposed directto the flame of an oxyhydrogen- 'blowpipe and kept in this position until its vitrification is accomplished, after which it is removed, or the piece is-thrown into a vessel of a suitable material, (carbon, iridium,or

the like,) which is heated up to the temperature necessary for the vitrification in a: furnace with an oxyhydrogen-blowpipe or in an electric furnace. In both cases a piece of quartz-glass free from air-bubbles is obtained.

Now a second piece is extracted from the glowing contentslof the crucible or othervessel and treated in the same mannerl The uniting of the vitrified pieces by melting them together successively to form the massmay be effected-in difierent ways.-

cation is effected 1 directly with an oxyhydrogen-blowpipe, the pieces'may be melted together. in the following manners: Two workmen having their own blowpipes work together, one extracting a piece of rockcrystal from the glowing'contents of the cru:

' .cible or vessel'and exposing it atonceto his blowpipe until its vitrification is effected, then giving it off at once to the other workman, who places it on the piece or rod .of melted quartz-glass which heis ,keeping before his blowpipe, so as to cause the piece to,

unite with the other piece of the rod by melting. The firstworkman thenextracts afresh piece from the crucible or vessel, andboth" workmen repeat the described operations. A single workman may perform alone the whole work by extracting a piece oflrock-crystal from the glowing crucible or'vessel and holding it to his blowpipe until the vitrification is accomplished. Then he keeps the vitrified piece ofglass still in the flame and extracts from the crucible or vessel a second piece of .rock-crystaL-heated up to a temperature of 600 centigrade, which he applies to the piece of quartz-glass and causes it to melt and unite therewith, and after this he extractsa fresh pieceof heated rock-crystal from the crucible or vessel and repeats the operation. Again the several pieces of heated rock-crystal are extracted one after another from the glowing contents of the crucible or vessel, exposed to the flame of the blowpipe, and turned into quartz-glass in the manner described, after which the several vitrified pieces are stored separately. 'Later on the uniting of these vitrified pieces may be accomplished either by the aid of the flame of an oxyhydrogen-blowpipe or in a furnace, in either case the sepa- '=5=rate vitrified pieces being successively addedtime. I

from this temperature to that required for the vitrification, and, third, the successive addition of the glowing pieces to the melting .mass.

What I claim as my invention, and desire to secure by Letters Patent, is'

1. The methodsubstantially as'herein described of producing quartz-glass free from air-bubbles, which consists in slowly heating pieces of rock-crystal to a temperature exceeding 600 centigrade, then bringing the pieces to the temperature of'vitrification and. 5p;

uniting the pieces by melting. A 2. The method substantially as,herein described of producing quartz-glass free from air-bubbles, which consists in slowly heating pieces of? rock-crystal to a temperature exceeding600 centigrade, then bringing the pieces successively to thetemperature of vitrification, and successively uniting the vitrir fied pieces together by melting. 3. Theimethod substantially as herein described of. producing quartz-glass free 'from air-bubbles, which consists in slowly heating pieces of rock-crystal to a temperature exceeding 600 centigrade in a crucible or the like, successively withdrawing the heated pieces and bringing them to the temperature of vitrification, and successively uniting the vitrified pieces by melting.

4:. The method substantially as herein de-' scribed of producing quartz-glass free from air-bubbles, which consists in slowly heating pieces of rock-crystal to atemperatureexceeding 600 centigrade in a crucible or the like, successively withdrawing the pieces by means of a heated tool and bringing the pieces" by exposing them to the flame of an oxyhy- 1 drogen blowpipe, and successively uniting the vitrified pieces by melting.

6. The method substantially as herein scribed of producing quartz-glass free f'r om air-bubbles, which consists in slowly heating pieces of rock crystal to a ter'nperatureeX-fl ceeding 600 centigrade, bringing the heated pieces to the temperature of vitrification by exposing to the flame of an oxyh'ydrogenblowpipe, storing the several vitrified pieces, and finally uniting the vitrified pieces by heating them and adding 'them'successively to the melting mass.

7. The method substantially as herein de scribed of producing quartz-glass free from air-bubbles, which'consists in slowly heating ceeding 600 centigrade in a crucible, successively withdrawing the pieces by means of a heated tool and bringing the pieces to' the pieces of rock-crystal to a temperature extemperature of vitrification .by exposingto the flame 'ofan oxyhydro'gen-blowpipe, stowing the several; vitrified pieces, and finally uniting the vitrified pieces by heating and successively melting them together to' form the mass.

, In testimony'w-hereof I have signedmy name I to this specification in the presence of two subscribing witnesses.

g RICHARD Kl jUH.

Witnesses: FRANZ' HAssLAoHER, f ERWIN 'DIPPEL. 

